Abstract: Objective To improve diagnostic and therapeutic levels of pneumocystis pneumonia (PCP) in non-HIVinfected patients. Methods The clinical data (including clinical manifestation，laboratory examination, imaging features,diagnosis, treatment and prognosis) of sixteen non-HIV-infected patients with acute respiratory failure caused by PCP who were diagnosed in our intensive care units (ICU) during January 2015 to December 2017, were summarized and discussed.Results Almost all patients were immunocompromised by hormone or immunosuppresant before PCP (15/16). Fever, dry cough, and dyspnea were the first symptoms in all patients. The development of PCP was rapid. All patients showed acute respiratory failure [oxygen index: (85.8±16.8) mmHg]. Invasive ventilator support was required in 11 patients (68.8%), high flow oxygen therapy was used in 5 patients (31.2%). The chest CT characteristics indicated diffuse ground glass opacity. Two patients were found methenamine silver-stained positive in bronchoalveolar lavage fluid. Sixteen cases were positive for pneumocystis detected by PCR. Sixteen patients were treated with compound sulfonamide (SMZco)，caspofungin and corticosteroid. Eight patients were cured, 7 died and 1 case was given up and then died. The ICU length of stay was 3-29 days, average days (13.0±7.1). Conclusion PCP is a kind of opportunistic infection among patients who are treated with immunosuppressive agents. SMZco combined with caspofungin and corticosteroid is effective in the treatment of severe PCP patients.

Key words: pneumonia, pneumocystis, respiratory insufficiency, sulfamethoxazole, non-HIV infections